Potassium Hydroxide → HCID 23450690, compound

Participants

Reaction Conditions

Reaction Steps

10.0 g (31.3 mmol) of the 8-chloro-6-ethoxycarbonyl-4-hydroxy-5-methylthiochroman-1,1-dioxide obtained in the above step (7) was dissolved in 30 ml of ethanol, and 50 ml of a 16% potassium hydroxide aqueous solution and 6.1 g (93.3 mmol, 3.0 equivalents) of a zinc powder were added. The mixture was stirred under heat at 50° C. for 3 hours. After the completion of the reaction, the zinc powder was filtered off. While the reaction mixture was cooled, a 2N hydrochloric acid aqueous solution was added until the mixture had a pH of 1. Then, the mixture was extracted with ethyl acetate twice. An organic layer was washed with a saturated sodium chloride aqueous solution and then dried over anhydrous sodium sulfate, and the solvent was distilled off to give 11.5 g (yield 100%) of 4-hydroxy-5-methylthiochroman-6-carboxylic acid-1,1-dioxide.

Provenance & Evidence